Thermal circuit-closure.



J; CARRIGANL THERMAL CIRCUIT CLOSURE.

APPLICATION FILED JULY 3. I913- 1,136,407, Patented Apr. 20, 1915.

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THERMAL cmcun CLOSURE. APPLICATION map JULY 3. 1913. 1 136 407 v Patented Apr. 20, 1915 2 SHEETS-SHEET 2.

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JOHN CARRIGAN, 0F SEATTLE, WASHINGTON.

THERMAL CIRCUIT-CLOSURE.

To all whom it may concern:

Be it known that I, JoHN CARRIGAN, a citizen of the United States, residing at Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Thermal Circuit- Closures; and I do hereby declare the following to be a full, clear, and exact description of the invent'on, such as Wlll enable others skilled in the art to which it appertains to make and use the same.

This invention relates to fire alarm systems, and specially to a combined thermally p provide an alarm system having suitable electrical devices whereby the systemmay be tested from time to time to determine the operability thereof.

In the accompanying drawing, Figure 1 represents a front elevation of the thermostat showing the same connected with the alarm circuit. Fig. 2 represents a vertical sectional view through the thermostat. Fig.

3 represents a vertical sectional, view there-- through taken at right angles to Fig. 2. Fig. 4 represents ahorizontal sectional view through the thermostat, and, Fig. 5 represents a detail view of the thermostat housing and cover therefor.

Referring to the drawings in detail, the numeral 1 indicates the base. of the housing which is adapted tobe secured to the wall of a room to be equipped with the alarm system. A porcelain plate 2 is fixed in the front end of the base 1 and carries an annular ring 3 which projects outwardly of the plate 2 and is provided with a removable cover 4 having a glass front 5. The removable cover 4 is provided with bayonet slots 6 which are adapted for locking engagement with lugs 7 carried by the ring 3. The plate 2 is provided with graduated markings 8 representing a preferred thermometric scale. An indicating hand 9 is pivoted on a shaft 10 mounted through the plate 2, and fixed on the opposite side of said plate to a thermostatic coil 11. The

opposite extremity of the coil 11 is-fixed and the extreme free end of to a post 12 Specification of Letters Patent.

Patented Apr. 20, 1915.

Application filed July 3,1913. Serial 110. 777,286.

the shaft 10 is mounted through a bracket 13 fixed to the rear side of the plate 2 by the screws 14. A, guard plate 15 is also secured to the rear side of the plate 2 for protecting the coil 11.

The under side of the ring 3 is slotted at 16 and the lower portion of the plate 2 is slotted at 17 to permit the atmospheric air to penetrate the casing for the thermostat and to reach the coil 11 to act thereon and actuate the indicator hand 9 to register the temperature within the room.

It will be iunderstood that the plate 2 is formed of porcelain or other suitable insulating material in which is formed an arcuate slot 18, located directly below the markings 8 and receiving a pair of adjustable contact posts 19 and 19. The posts 19 and 19 carry conductors 20 and 20*, respectively,

secured in the wall of the base 1. Asecond contact element 22 is suitably fixed to the shaft 10 and carries a conductor 23 .positioned through an insulating sleeve 24 also fixed in the side of the base 1.

The conductors 20 and 20 are joined within the sleeve 21 which extends from the'thermostat and is connected at its opposite extremity to. two sets of batteries A and B. The other conductor 23 of the thermostat is connected with an electrical alarm bell C, an annunciator D and lamp E by suitable branch conductors F. The electrical devices C, D and E are also connected by the conductor G and branch conductors H to the ppposite pole of the bat teries A and B.

which extend through an insulating sleeve 21 The circuit thus described including the either of the contact posts 19 and 19 Thus the circuit is closed through the batteries A and B, conductor 20, either contact post 19 or 19, hand 9, conductor 23, the several branch conductors F, the electrical devices C, D and E, and returning to the batteries A and B through the conductor G and branch conductors H.

A, suitable push button I, or other circuit closin g'device 1s connected with the conductors 20 and 23 intermediate the thermo-\ statland the electrical devices D and E for testing the condition of the batteries 5 A and B.

What I claim is A thermostat comprising a housing having an outturned flanged edge, an insulating plate having a central aperture and an arcuate slot therein attached to said flanged edge,

a thermostat coil mounted in said housing, a

shaft connected to said coil to be actuatedthereby and running through said central aperture, a needle attached to said shaft and actuated thereby, and a plurality of contact posts adjustably mounted in said arcuate slot and adapted to be contacted v with by'saidneedle to close an alarm circuit,,said contact posts consisting of a shaft portion having a head portion at one end and a threaded portion at the opposite end, adapted to adjustably play through said arcuate slot, a washer mounted on said shaft between said head portion and said insulating plate adapted to bind a circuit wire between said head portion and said washer and to rest against said plate, and a sleeve- 

